As technologies keep developing, users can be provided with more types of mobile terminal products, for example, smartphones, tablet computers, and e-books. These mobile terminal products almost all have a wireless network Wi-Fi access function. This provides great convenience for users to surf the Internet by using mobile terminals.
However, when a user accesses an AP (Wireless Access Point, wireless access point) to surf the Internet by using a mobile terminal, a position of the mobile terminal may change as a position of the user changes. When the mobile terminal is closer to the AP, a signal of the AP received by the mobile terminal is stronger. When the mobile terminal is farther away from the AP, a signal of the AP received by the mobile terminal is weaker.
Currently, regardless of whether a mobile terminal accesses an AP that has a weaker signal or an AP that has a stronger signal, a Wi-Fi module of the mobile terminal operates at a fixed transmit power. For example, when a mobile terminal accesses an AP that has a relatively weak signal, to obtain good quality of data transmitted between the mobile terminal and the AP as much as possible, a Wi-Fi module of the mobile terminal is usually configured to operate always at a maximum transmit power. However, when the signal of the AP accessed by the mobile terminal becomes stronger, the Wi-Fi module of the mobile terminal still operates always at the maximum transmit power. This inevitably increases power consumption of the mobile terminal. In addition, because a battery capacity of the mobile terminal is limited, if the mobile terminal accesses the AP always at the maximum transmit power, battery power is consumed excessively quickly, and therefore a battery life of the mobile terminal is severely affected.